Conformance Control in Oil Reservoirs by Citric Acid-Coated Magnetite Nanoparticles

Area of Science:

• Materials Science
• Petroleum Engineering
• Nanotechnology

Background:

• Excessive water production in oil and gas reservoirs poses significant financial and environmental challenges.
• Effective water shutoff and conformance control are crucial for optimizing enhanced oil recovery (EOR) technologies.

Purpose of the Study:

• To compare the water shutoff performance of citric acid-coated magnetite (CACM) and hematite nanoparticles (NPs) against polyacrylamide polymer solution.
• To evaluate the efficacy of CACM NPs in heterogeneous and homogeneous micromodels for improved oil recovery.

Main Methods:

• Facile one-step synthesis of reusable, environmentally friendly CACM NPs.
• Characterization of NPs using FTIR, FESEM, DLS, and XRD.
• Performance evaluation in 2D micromodels under varying magnetic field intensities.

Main Results:

• Uniform spherical Fe3O4 NPs (40 nm avg. diameter) coated with citric acid were synthesized.
• CACM NPs formed a solid-/gel-like structure in a magnetic field, creating a high pressure drop and plugging efficiency.
• Achieved a resistance factor of 3.5 and residual resistance factor of 2.14 for heavy oil in a heterogeneous micromodel.

Conclusions:

• CACM NPs demonstrate significant potential for water shutoff by forming magnetic field-responsive gel structures.
• This smart fluid technology offers a promising, environmentally friendly approach to reduce water production in oil reservoirs.
• Further innovation in field equipment design is needed for practical application of magnetic field-responsive fluids.